Apparatus for Filling Containers According to Weight

ABSTRACT

The invention relates to an apparatus for the weight-dependent filling of containers, especially bottles ( 3 ), which comprise a tubular neck section ( 7 ) and which consists of a fill nozzle ( 8 ), a weighing device ( 5 ) and a holding element ( 6 ) for holding the container ( 3 ) under the fill nozzle ( 8 ). In that regard the weighing device ( 5 ) includes a force uptake element ( 14 ), a force introduction element ( 15 ) and a deformation body ( 17, 18 ) that is arranged therebetween and that is provided with strain gages ( 24 ) applied thereon. In that regard, the force uptake element ( 14 ) is secured on a machine frame ( 2 ) and the holding element ( 6 ) is secured on the force introduction element ( 15 ). The invention is characterized in that the force uptake element ( 14 ) is embodied as an outwardly lying ring element ( 14 ) and the force introduction element is embodied as a coaxially inwardly lying ring element ( 15 ), between which at least one radially spring-elastic connecting web ( 17, 18 ) is arranged as the deformation body. In that regard, the holding element ( 6 ) is secured on the inwardly lying ring element ( 15 ) therebelow.

The invention relates to an apparatus for the weight-dependent fillingof containers, especially bottles according to the preamble of thepatent claim 1.

In the beverage industry, large quantities of containers, especiallybottles of glass or plastic, are filled with beverages or other liquidfoodstuffs in very short time segments. Also in other branches ofindustry it is often necessary to fill determined quantities of liquidsinto containers with screwable fill openings. For that purpose, mostlyautomatic filling equipment stations are used, which are embodied ascarousel or rotational filling machines especially in the beverageindustry. In that regard, the containers or bottles are directed from asupply belt onto a circulating path or track on the circumference of therotational filling machine, on which a plurality of filling nozzles orfilling stubs are arranged uniformly distributed above the circulatingcontainers. During the circulation on this rotational filler, thenvalves located in the filling nozzles are opened and again closed uponreaching a prescribed fill level. Thereafter, the filled and closedcontainers leave the circumferential area of the rotational filler andare further conveyed with a relatively high uniform speed via an outletconveyor belt.

Such a rotational filling equipment station is known from the EP 0 893396 B1, which is provided for the automatic filling of plastic bottleswith a liquid. In that regard, the bottles are directed onto thecirculating path on the circumference of the filling equipment stationrespectively under a filling nozzle with a fill valve, whereby thebottle neck is fixed by a holding element under the filling nozzle.During the rotational circulation or revolution, now the fill valve isopened and the liquid is let into the bottle until apparently aprescribed quantity is filled-in. In this regard, it apparently relatesto a volumetric filling, which is not suitable for all liquids orbottles.

A weight-dependent filling is known from the DE 698 08 118 T3, whichprovides an outwardly flaring or collared weight determination andholding support of a bottle under a filling nozzle. Thereby similarly afilling equipment station of a carousel type is provided, whichdiscloses a rotatable platform for the filling of the bottles. Thisfilling apparatus is provided exclusively for plastic bottles thatcomprise a laterally protruding circumferential collar around thecylindrical neck under their pipe-shaped or tubular fill opening. Forthis, a weighing device is provided, which includes a bending beamweighing or load cell. This is embodied as a double bending beam, whichconsists of an elongated square-section rod, into which two throughgoinghorizontal bored holes are laterally let-in, and are connected with oneanother by a recess lying therebetween. The lateral horizontal boredholes form two thin locations at the beam upper side and beam lowerside, which represent a deformation body, onto which strain gages fordetermining the weight force are applied. In that regard, the onehorizontal end of the clamped-in bending beam represents a force outputelement, which is connected with the frame of the rotating fillingequipment station. The oppositely lying end of the bending beam therebyrepresents the force introduction element, onto which a holding elementis secured. In that regard, the holding element extends laterallyoutwardly flared or collared away from the bending beam and from theframe of the filling apparatus. In that regard, the holding elementconsists of two horizontal, laterally rotatably supported flat jaws,which are held together by means of a spring and which comprise a roundopening on its outwardly flared or collared end. Regarding the suppliedbottles, these are guided with their neck or throat into the opening insuch a manner, so that the collar lies on the upper jaw surface, so thatthe bottles are fillable while freely suspended in the holding element.For filling the bottles, a filling nozzle is arranged above the opening,and after opening a valve the liquid is filled into the bottle throughthe filling nozzle. Due to the support of the collar on the jaws of theholding element, during the rotating filling process, the weight forceis introduced into the force introduction element of the weighingdevice, which is rigidly clamped-in relative to the frame of the fillingequipment station. Thereby a strain is produced in the deformation body,which is proportional to the weight of the bottles, and which isdetected by the strain gages. Upon reaching a prescribed fill weight,then the inflow through the filling nozzle is stopped and the fillingprocess is ended. Such a filling apparatus has the disadvantage, that itis only suitable for the filling of plastic bottles with a collar thatextends around the neck, and requires a laterally large structural spacefor the arrangement of the rod-shaped load cell.

From the DE 39 04 714 A1, however, also a force measuring ring is known,which requires only a small outwardly flaring or collared structuralspace. This force measuring ring consists of two ring elements that arearranged coaxially within one another, whereby the upper inner ringelement is connected radially with the outer lower ring element by twomovable bending springs as deformation bodies. For detecting the forceintroduced into the upper ring, the bending springs are equipped withstrain gages. Even if this force measuring ring comprises a throughgoinghollow central opening, it is not apparent how it would be usable forthe filling of containers according to weight.

Therefore, it is the underlying object of the invention to provide anapparatus for the weight-dependent filling of containers, which requiresonly a small outwardly flaring or collared structural space and is alsousable for containers or bottles without collars.

This object is achieved by the invention set forth in patent claim 1.Further developments and advantageous example embodiments of theinvention are set forth in the dependent claims.

The invention has the advantage that the central inner annular hollowspace can be used for leading through the filling liquid, due to thering-shaped or annular embodiment of the weighing device. Thereby a verycompact filling apparatus can be achieved, which can be constructedshort both in its axial length as well as in the outwardly flaring orcollared area, and advantageously requires only a small structuralspace, which barely extends beyond the diameter of the container to befilled.

The invention further has the advantage that no lever arm acts on themeasuring element due to the symmetrical arrangement of the holdingelement on the inner ring of the weighing device, so that the weighingdevice is not at the same time overloadable even with larger fillingpressure jolts or peaks. The largely rotationally symmetrical embodimentof the weighing device additionally has the advantage that thereby ahigh weighing accuracy can be achieved, because due to the centralholding support and filling of the liquid into the container, only smallinterfering bending moments can act on the measuring arrangement orcompensate one another due to the symmetrical arrangement.

The invention additionally has the advantage that due to the central andaxial arrangement of the holding element below the weighing device,thereby all containers with central filling openings are fillable in aweight-dependent manner, whereby it does not depend on the presence of acollar on the container.

Simultaneously, such a holding support centrally below the weighingdevice has the advantage that therewith also containers having variousdifferent lengths are fillable, without adjustments of the fillingapparatus being necessary for that. With a correspondingly adaptedholding element, therefore weight-dependent fillings of glass bottleswith crown cap necks or threaded necks as well as of plastic bottleswith only a threaded neck are also possible, and this with a highfilling accuracy.

In a particular embodiment of the weighing device it is provided toenclose the radial internal area between the two ring elements at thetop and the bottom by a simple flexurally soft cover. This has theadvantage that thereby a hermetic sealing of the inwardly arrangedsensitive measuring elements is possible, without a separate housingbeing necessary for that. With a particular embodiment of the flexurallysoft cover, additionally still a coaxially encircling load relief grooveis provided, whereby even small interfering force shunt effects are alsoreducible.

The invention is explained in more detail in connection with an exampleembodiment, which is illustrated in the drawing, wherein:

FIG. 1 shows a cutaway section of a filling equipment station with afilling apparatus mounted thereon;

FIG. 2 shows a perspective plan view onto an upwardly open weighingdevice;

FIG. 3 shows a perspective plan view onto a downwardly open weighingdevice; and

FIG. 4 shows a perspective sectional view through a hermetically sealedweighing device.

In FIG. 1 of the drawing, there is illustrated a cut-away section of acarousel filling equipment station 1 and mounted thereon, an apparatusfor the weight-dependent filling of bottles 3 as containers. Theapparatus includes a weighing device 5 screwed onto a rotor plate 4, onwhich weighing device, a holding element 6 is arranged thereunder and afill nozzle or pipe stub 8 is guided from the top axially throughgoingto the bottle neck 7 centrally through the weighing device 5.

The carousel filling equipment station 1 includes a machine frame 2which rotates during the filling operation, and on which a rotor plate 4is arranged as a part in an overhanging or collar-protruding manner atthe top. A fill pipe 9 is arranged from a liquid container, which is notshown, on the machine frame 2 to each filling apparatus spaced apart onthe circumference of the rotor plate 4, whereby the fill pipe 9 isguided through the rotor plate 4 and centrally through the weighingdevice 5, and the fill nozzle or pipe stub 8 thereof ends above the fillopening on the bottle neck 7. The filling apparatus may, however, alsobe provided on a linear filling equipment station.

A U-shaped holding bail 10 is provided as the holding element 6, whereinthe holding bail is open radially to the supply or infeed direction ofthe bottles 3 and comprises two horizontally oriented parallel shanks11. In that regard, the upper shank 11 is tightly screwed onto thebottom side of the weighing device 5 and has a through passage openingfor guiding through the fill nozzle 8. The lower shank 11 of the holdingelement 6 preferably comprises a recess that is open toward the frontand that corresponds to at least the diameter of the bottle neck 7.However, embodiments with clamping jaws and adaptations for fixing on athreaded rim or on a crown cap rim are also usable as the holdingelement 6.

The illustrated embodiment with the recess open toward the front isprovided for the resting contact of the collar 12 situated on the bottleneck 7, as it is typical in current commonly used plastic bottles.During the filling of the bottles 3 or other containers with a centralupper cylinder-shaped fill opening, due to the weight of the bottle 3and the respective contents thereof, the gravimetrically downwardlyacting weight force F_(G) is introduced via the holding element 6 intothe weighing device 5. Upon reaching a prescribed weight force F_(G) asthe filling weight, then a valve, which is not shown but which issituated in the fill pipe 9, is closed so that the filling process isended and, for example, a bottle 3 filled with a beverage can be furtherconveyed for closing it.

The weighing device, which is screwed from the bottom onto the rotorplate 4 of the machine frame 2, is shown in detail in FIG. 2 and FIG. 3of the drawing. In that regard, FIG. 2 of the drawing shows a weighingdevice 5 open toward the top, with the four symmetrically arrangedthrough-bores 13 provided for the screw-connection. In that regard, theweighing device 5 is embodied as an essentially rotationally symmetricalload cell that comprises, as a force uptake element 14, a radially outerring element as a narrow outer ring. In that regard, the load cell 5 ismachined as one piece out of a short massive round rod by achip-removing machining process, and therefore has only a smallhysteresis. In that regard, the base body 38 produced thereby preferablyconsists of a spring-elastic stainless steel alloy, aluminum ortitanium. The base body could, however, also be produced of ceramic inPIM technology (Powder Injection Molding) or in MIM technology (MetalInjection Molding), which would have to be ground after the powderinjection molding process so as to maintain accurate dimensions.

A radially inwardly lying ring element as a force introduction element15 is arranged as an inner ring lying coaxially inwardly relative to theouter ring 14, wherein the inner ring surrounds or encloses acylinder-shaped central hollow space 16, through which the fill nozzle 8is guided through in a contact-less manner. Preferably two radialconnecting webs 17, 18 are machined out of a previously remainingintermediate ring 19, between the outer ring 14 and the inner ring 15,on a horizontal center plane 31, wherein the connecting webs 17, 18represent the two deformation bodies lying 180° radially opposite oneanother, by which the force uptake element 14 is connected with theforce introduction element 15 of the load cell 5 in a spring-elasticmanner.

For that purpose, an axially through-going outer ring groove section 20is milled into the previously solid intermediate ring 19 in the area ofthe outer ring 14 on a circumferential range or region of approximately235°, and lying 180° radially opposite thereto in the area of the innerring 15 a further axially through-going inner ring groove section 21 ofsimilarly approximately 235° is milled into the previously solidintermediate ring 19. Thereby, a first connecting web 17 and lying 180°radially opposite thereto a second connecting web 18 have arisen betweenthe overlapping ring groove sections 20, 21, whereby the connecting websconnect the outer ring 14 and the inner ring 15 radially with oneanother and extend on a respective tangential ring web section 34 ofapproximately 60° concentrically to the inner ring 15. Two paralleltransverse grooves 22 with a semicircular cross section are milled intothese two oppositely located concentric ring web sections 34 of theconnecting webs 17, 18 from the top side of the load cell 5. Theserespectively form two thin locations 23 in the connecting webs 17, 18,and respectively two strain gages 24 as sheer stress transducers areapplied on the opposite planar web surface thereof, as this can be seenin more detail from FIG. 3 of the drawing.

In that regard, FIG. 3 of the drawing shows a side of the load cell 5that is open toward the bottom. In that regard, the load cell 5 isembodied on its bottom side approximately symmetrically to the top side,whereby however no transverse grooves 22 are milled into the web bottomsides 25. Thereby the strain gages 24 can be applied very exactly on theplanar surfaces of the thin locations 23.

For mounting the holding bail 10, the inner ring 15 is provided with awidened wall thickness toward the bottom side and with foursymmetrically distributed threaded bored holes as securing bores 26.Furthermore, the outer ring 14 is flattened in a narrow area of itsouter circumferential surface, where a sealed cable inlet 27 is arrangedfor the connection of the weighing electronics and the strain gages.

The connection to the weighing electronics via the cable inlet 27 isvisible in detail from FIG. 4 of the drawing, which illustrates the loadcell 5 as a side view in section. This FIG. 4 simultaneously shows aparticular embodiment of the invention in which the weighing electronics33 is integrated in the load cell 5 and the inner space is hermeticallyclosed by two membrane-like covers 28, 29. In that regard, in FIG. 4 ofthe drawing, the load cell 5 is illustrated reversed relative to theinstallation position, whereby the bottom side of the load cell 5 issealed by a flexibly elastic lower membrane-like cover 28, which isarranged between the outer circumference of the inner ring 15 and theinner circumference of the outer ring 14 and is hermetically tightlywelded therewith. In a similar embodiment and arrangement, also theupper cover 29 is applied or installed on the oppositely lying load cellside. In that regard, the covers 28, 29 preferably consist of amembrane-like thin stainless steel sheet metal of approximately 0.1 mmthickness, which is well weldable with the edges or rims of the ringelements 14, 15. For improving the weighing accuracy, especially forreducing a possible force shunt effect, a concentric load relief groove30 with a triangle-shaped or semi-circular cross section is impressed orembossed into each cover 28, 29, whereby the groove comprises a radialflexurally soft structure.

Moreover, still additionally a radially encircling holding ring 32 isapplied on one side on the inner wall of the outer ring 14 above thehorizontal center plane 31, and an electronic circuit board 33 with theweighing electronics is secured on this holding ring 32. Hereby thestrain gages 24 are circuit-connected preferably to form a Wheatstonemeasuring bridge, are supplied with a supply voltage, amplify themeasuring signals, digitize the measuring signals and modulate themeasuring signals for transmission. The transmission can also be carriedout with a bus system. In a different embodiment of the fillingapparatus, the weighing electronics is integrated in the connectingcable.

The filling process in the filling equipment station 1 proceeds asfollows.

In rapid succession, the bottles 3 are delivered from a supply belt tothe carousel filling equipment station 1, and with their collars 12 arehung into the holding bail 10 of the holding element 6 in a mannerfreely suspended or floating under the fill nozzle 8. Then during therotational turning of the rotor plate 4, by opening an inlet valve thebottle 3 is continuously filled. Thereby the weight is introduced viathe holding bail 10 into the inner ring 15 as the force introductionelement, of which the force effect produces a maximum strain in the thinlocations 23 of the connecting webs 17, 18. This is proportional to theweight force F_(G), and it is converted by the strain gages 24 into anelectrical weight signal and transmitted to an evaluating circuit.There, during the filling process, this weight signal is compared with aprescribed filling weight, and upon reaching it the filling process isended. The above described load cell 5 involves a highly accuratecalibratable embodiment preferably with a nominal weight range of 10 kgand an accuracy of +/−0.5 g to +/−1.0 g.

With such a filling apparatus, preferably beverages are filled intoplastic bottles having a 1.0 to 1.5 l content volume, whereby therewithalso bottles 3 and containers from 0.33 to 5.0 l content volume arefillable with calibratable accuracy. The illustrated embodiment of theload cell 5 with a nominal load of 10 kg in that regard preferably hasan outer diameter of approximately 90 mm and a height of approximately40 mm. Thereby the load cells 5 can be arranged next to one anotherapproximately at the bottle diameter of 1.5 l bottles 3 about the rotorplate 4, in order to be able to simultaneously fill the largest possiblenumber of bottles 3 or containers.

The central hollow space 16 of the inner ring 15 preferably has adiameter of 27 mm, so that thereby typical fill nozzles 8 forconventional bottle openings can be guided therethrough, so that a rapidfilling is ensured, without there being a danger of contacting the forceintroduction element 15. With such a load cell 5, with correspondingdimensioning of the deformation bodies 17, 18, it is, however, alsopossible to produce embodiments with smaller nominal loads of forexample 2 kg and larger nominal loads of for example 50 kg. In thatregard, the weight-dependent filling apparatus is not only usable forliquids, but also for friable or flowable or dust-type fill materials.

In the embodiment of the holding element 6, not only mechanical holdingbails 10 for the resting contact of a bottle collar 12 are usable, butrather all embodiments in which the container is fixable symmetricallyto the fill opening 8. Thus, also electrical, hydraulic, pneumatic ormagnetic clamping systems are conceivable, by which the bottle necks,container threadings, or cans can be held centrally under the fillnozzle 8.

1. An apparatus for the weight-dependent filling of containers,especially bottles (3), having a tubular neck section (7), wherein theapparatus comprises a fill nozzle (8), a weighing device (5) and aholding element (6) for holding the container (3) under the fill nozzle(8), and in which the weighing device (5) includes a force uptakeelement (14), a force introduction element (15) and a deformation body(17, 18) arranged therebetween and with strain gages (24) applied on thedeformation body, whereby the force uptake element (14) is secured on amachine frame (2) and the holding element (6) is secured on the forceintroduction element (15), characterized in that the force uptakeelement is embodied as an outwardly lying ring element (14) and theforce introduction element is embodied as a coaxial inwardly lying ringelement (15), between which at least one radially spring-elasticconnecting web (17, 18) is arranged as the deformation body, whereby theholding element (6) is secured to the inwardly lying ring element (15)therebelow.
 2. The apparatus according to claim 1, characterized in thatthe fill nozzle (8) is guided from the top through a central hollowspace (16) of the weighing device (5) at least to the fill opening ofthe container (3). 3-16. (canceled)
 17. The apparatus according to claim1, characterized in that the weighing device is embodied as arotationally symmetrical load cell (5), which includes a one-piece basebody (38), which consists of the inner ring (15) and the coaxiallysurrounding outer ring (14) and the at least one connecting web (17, 18)arranged radially therebetween.
 18. The apparatus according to claim 17,characterized in that the one-piece base body (38) consists of aspring-elastic stainless steel, aluminum, titanium or ceramic.
 19. Theapparatus according to claim 1, characterized in that the outer ring(14) and the inner ring (15) are connected with one another in africtional or force-coupling manner by two connecting webs (17, 18)lying radially 180° opposite one another in a horizontal center plane(31).
 20. The apparatus according to claim 1, characterized in that eachconnecting web (17, 18) consists of a first radial web section (35) thatis connected with the inner ring (15) and a second radial web section(36) that is connected with the outer ring (14), and a tangential ringweb section (34) lying therebetween.
 21. The apparatus according toclaim 20, characterized in that each tangential ring web section (34)comprises two tangentially spaced-apart transverse grooves (22), whichform two spring-elastic thin locations (23), on which strain gages (24)are applied.
 22. The apparatus according to claim 21, characterized inthat the connecting webs (17, 18) are formed by two axially throughgoingring groove sections (20, 21) that lie radially opposite one another,whereby an inner ring groove section (21) extends on the inner ring (15)and an outer ring groove section (20) extends on the outer ring (14).23. The apparatus according to claim 22, characterized in that both ringgroove sections (20, 21) extend on a radial angular range of the loadcell (5) of approximately 235° and overlap one another on their ends ona range of approximately 60°, whereby the tangential ring web sections(34) extend on a tangential angular range of about 60°.
 24. Theapparatus according to claim 1, characterized in that the load cell (5),symmetrically to its longitudinal axis (37), comprises a throughgoingcentral hollow space (16), which serves for the contact-lessthrough-guidance of the fill nozzle (8).
 25. The apparatus according toclaim 1, characterized in that the outer ring (14) and the inner ring(15) are hermetically tightly connected at their axial end areas with alower cover (28) and an upper cover (29).
 26. The apparatus according toclaim 25, characterized in that the covers (28, 29) respectively consistof a membrane-like thin metal sheet, which is welded to the ringelements (14, 15).
 27. The apparatus according to claim 25,characterized in that the covers (28, 29) comprise at least one loadrelief groove (30), which is impressed or embossed thereinconcentrically to the inner ring (15), and which has a radiallyflexurally soft structure.
 28. The apparatus according to claim 1,characterized in that at least one holding ring (32), which is securedon one side on the outer ring (14), is provided in the inner space ofthe load cell (5) above or below a center plane (31), and an electroniccircuit board (33) with a weighing electronics is secured on the holdingring.
 29. The apparatus according to claim 1, characterized in that asealed cable inlet (27) is arranged on a circumferential surface of theouter ring (14), which serves for the connection of the weighingelectronics or regarding which the weighing electronics is integrated inthe connection cable.
 30. The apparatus according to claim 1,characterized in that the holding element (6) is embodied as a radiallyoutwardly open U-shaped holding bail (10), of which the lowerhorizontally oriented shank (11) has a radially outwardly open recessthat serves for receiving the bottle neck (7) and/or for verticallyfixing the container.